The series doesn't have enough substance regarding story to make a series, so they have to make shit up. If the series was to be true to the games, it would be limited exclusively to an action show, or an intellectual shonen as each belmont has its own season and grows against adversity surviving inside the castle, as they meet strange creatures and characters and each stand alone is a fight or the character grows
That should've been the main concept for Castlevania as a TV series, pretty much a jojo-clone with the belmont clan instead, and the gameplay being the main concept for each season (Trevor is friends abilities, Simon is tools, Soma would be soul consumption) and use said gameplay for narrative and substance ideas, kind of how Star Trek uses sci fi to create potential for writing material and character growth.
The Netflix castlevania is shit for anyone with standards. The only nice thing about it is that they bothered playing with the IP. but netflix is really retarded when it comes to execution. See: Death note movie